Risk Estimation
Risk estimation in occupational health and safety is the process of determining the level of risk associated with a hazard by combining the likelihood of exposure causing harm with the severity of potential harm, often considering frequency and duration of exposure. It is typically expressed using a rating system (e.g., high/medium/low or numeric scores) to prioritize controls and is a key step in risk assessment under WorkSafeBC and OSHA guidelines.
On a BC shop floor, risk estimation is part of the hazard identification and risk assessment (HIRA) process, legally required for tasks like operating CNC mills, manual handling, or welding. The workflow includes identifying hazards, describing harmful events, estimating likelihood and severity using WorkSafeBC questions (e.g., injury type, exposure frequency, number of workers), and recording risk levels in systems like SafeDesk. High-risk hazards are prioritized for controls per the hierarchy of controls, and residual risk is reassessed. Specific assessments are required for violence, MSI, or hazardous substances, ensuring systematic documentation for compliance.
How does WorkSafeBC conceptually separate hazard identification, risk estimation, and risk evaluation within risk assessment?
Hazard identification finds what can cause harm. Risk estimation determines the level of risk by combining likelihood and severity, considering exposure frequency/duration and number of people exposed. Risk evaluation compares the estimated risk to acceptability criteria to decide if additional controls are required. WorkSafeBC bundles estimation and evaluation under 'assessing risks,' but the rating step is risk estimation, and decisions about sufficiency are risk evaluation.
In a BC manufacturing context, what variables should SafeDesk capture to perform defensible risk estimation aligned with WorkSafeBC expectations?
SafeDesk should capture hazard characteristics (type, consequence type), exposure parameters (number of workers, frequency, duration, vulnerable workers), likelihood factors (historical incident data, industry experience), control state (engineering, administrative, PPE, reliability, emergency response), and a risk rating framework (clearly defined scales for likelihood and severity, calculation method, documented residual risk). This aligns with WorkSafeBC's requirement for systematic, recorded risk assessments.
How should risk estimation differ for routine operations vs. low-probability, high-consequence events under WorkSafeBC Part 5?
For routine operations, likelihood is often higher, and estimation focuses on task frequency, exposure duration, and existing controls. For low-probability, high-consequence events (e.g., catastrophic tank failure), WorkSafeBC Part 5 requires a dedicated risk assessment with a qualified person, considering foreseeable causes, hazardous properties, population at risk, control effectiveness, and emergency response. Likelihood may be very low, but severity extreme, requiring advanced methods like fault trees or quantitative risk analysis.